The present invention provides a heat exchanger and, more particularly, a heat exchanger having a tank formed from two single sheets of aluminum.
Presently, most heat exchanger units for use in motor vehicles (e.g., radiators and charge air coolers) are made by mounting aluminum tubes and fins between two tanks (also sometimes referred to in the art as manifolds) that act as reservoirs for the liquid to be cooled. In charged air cooler applications, the heat exchanger comprises a cast aluminum tank that is welded to an aluminum header. In radiator applications, the tank usually consists of an aluminum header and a plastic tank. A plurality of tubes are connected to the aluminum header, which is then crimped to the plastic tank using a rubber O-ring as a sealing element to create a leak-proof vessel. The plastic tank is typically molded so as to provide mounting points for attachment of the heat exchanger to the motor vehicle and also to provide mounting points for accessories that are mounted to the heat exchanger.
One of the problems associated with heat exchangers of the type described in the previous paragraph is that fluid can leak from the tank at the O-ring joint. Furthermore, the plastic tank tends to warp during and after processing, which can also lead to additional leaking and assembly problems. Moreover, recycling of this type of heat exchanger is problematic because the plastic tank must be mechanically separated from the remaining parts of the heat exchanger.
The present invention provides a heat exchanger comprising a tank, a plurality of tubes in fluid communication with the tank, and a plurality of fins extending between the tubes. The tank consists essentially of a header member and a cover member, each of which is formed from a single sheet of aluminum. The header member includes an elongate generally planar base section having first and second ends and a middle portion disposed between the first and second ends. The header member also includes a flange section that extends along one edge of the base section and a wall section that extends along the opposite edge of the base section. The cover member has a central section that is spaced apart from the middle portion of the header member and a periphery that is joined to the first and second ends of the base section, the flange section, and the wall section. The cover member is preferably joined to the header member by brazing. The heat exchanger can accommodate mounts for mounting the heat exchanger to motor vehicle or for mounting various accessories to the heat exchanger at virtually any location adjacent to the joint between the cover member and the header member.
A heat exchanger according to the present invention preferably comprises an all-aluminum structure, meaning that the plurality of tubes, plurality of fins, and tank are all constructed of aluminum. Thus, the heat exchanger requires no disassembly in order to facilitate recycling. Furthermore, a heat exchanger according to the present invention does not rely on rubber O-rings to insure a seal between the tank and header. Therefore, a heat exchanger according to the present invention is less prone to leakage from fatigue or heat stresses.
The foregoing and other features of the invention are hereinafter more fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the present invention may be employed.